Treatment outcome and prognostic factors of external auditory canal squamous cell carcinoma: A retrospective study in a tertiary center

Objective: Squamous cell carcinoma (SCC) of the external auditory canal (EAC) is a rare malignancy with various treatment strategies and outcomes. The purpose of this study was to evaluate the clinical characteristics and survival outcomes and identify prognostic factors in patients with SCC of EAC. Methods: Twenty-one patients with SCC of EAC treated in a single tertiary center between 2009 and 2021 were retrospectively reviewed and analyzed. The modified Pittsburgh classification system was applied for staging. Factors associated with survival were identified by univariate survival analysis. Results: The mean age at diagnosis was 61 years (range: 41–79 years). Early-stage (T1 + T2) accounts for 38.1% of the series and advanced-stage (T3 + T4) accounts for 61.9%. Eighteen (85.7%) patients underwent primary surgery with curative intent. The 5-year overall survival rate of the 21 patients was 67.4%. Tumor invasion to the otic capsule, eustachian tube, sigmoid sinus, and dura were associated with poor prognosis in univariate analysis (p =.046;.008;.027; and.08, respectively). Conclusions: Factors predictive of less favorable survival include the history of COM, tumor invasion to the otic capsule, eustachian tube, sigmoid sinus, and dura. It is important to make a precise and systemic preoperative evaluation of disease extent. Level of Evidence: 4.